Refrigerator/freezer safety device

ABSTRACT

A device is described for opening the door of an enclosure, more particularly the magnetically held door of a refrigerator, freezer, or the like, which device is responsive to the temperature within the enclosure to open and hold the door thereof, to allow heat dissipation therefrom and air circulation therein, when the temperature within such enclosure exceeds a certain temperature.

United States Patent 91 Vallee et al.

[451 Sept. 10, 1974 REFRIGERATOR/FREEZER SAFETY DEVICE Inventors:Richard E. Vallee, 619 S. Bourbon St., Blanchester, Ohio 45107; GeraldE. Vallee, 30 Burkhart Ln., Gallipolis, Ohio 45631 Filed: Jan. 24, 1973Appl. No.: 326,386

U.S. Cl. 49/2, 49/31 Int. Cl E05f 15/20 Field of Search 49/1, 2, 31;

160/1-6; 292/DIG. 65, DIG. 66

References Cited UNITED STATES PATENTS 3/1935 Flegel 49/2 X 7/1952 Derbyet al. 49/2 X 10/1956 Buckley 292/DIG. 66

2,808,2 8] 10/1957 Poe 292/D1G. 65 2,830,547 4/1958 Zicche 292/DlG, 652,893,772 7/1959 Edwards 292/DIG. 65 3,139,022 6/1964 Koplar 49/2FOREIGN PATENTS OR APPLICATIONS 291,718 10/1967 Australia 49/1 PrimaryExaminer-Dennis L. Taylor [5 7] ABSTRACT A device is described foropening the door of an enclosure, more particularly the magneticallyheld door of a refrigerator, freezer, or the like, which device isresponsive to the temperature within the enclosure to open and hold thedoor thereof, to allow heat dissipation therefrom and air circulationtherein, when the temperature within such enclosure exceeds a certaintemperature.

5 Claims, 4 Drawing Figures mammsm 0:924

FIGURE I FIGURE 2 FIGURE 4 FIGURE 3 REFRIGERATOR/FREEZER SAFETY DEVICEBACKGROUND OF THE INVENTION This invention relates to door openers andmore particularly to a door opener for use as a safety device onrefrigerators, freezers and other airtight or semiairtight enclosures.

Refrigerators, freezers, and the like, particularly those which havebeen abandoned, have been a source of danger for small children whomight crawl inside such an enclosure and then become inadvertentlytrapped therein when the door of the enclosure closes. [See: HearingBefore a Subcommittee on the Committee on Interstate and ForeignCommerce, House of Representatives, 88th Congress, First Session, onProgress to Date in Achieving the Objectives of Public Law 930, 84thCongress, Sept. 23, 1963 (US. Government Printing Office, 1964)].

Measures have been taken from time to time to eliminate the dangers tochildren which such enclosures present. For example, statutes have beenpassed in many jurisdictions to require the owner to remove the lock orhinges from the doors of refrigerators, ice boxes, or other airtight orsemi-airtight containers, before discarding or otherwise abandoningthem, to pre vent persons from being trapped therein. In addition, mosthousehold refrigerators and freezers are no longer built with positiveoutside mechanical latching devices for securing the doors thereof, butare usually equipped with magnetic door gaskets or latches, with certainrestrictions on the maximum force required to break the seal of such amagnetic closure. Further, devices such as door unlatching mechanismsactivated from the interior of the door have been provided for such aslarge walkin refrigeration units, but such devices have not found use onsmaller units, such as household units, because of complexity,prohibitive cost, or other objectionable features. These measures havenot been entirely successful as evidenced by frequent deaths of childrenresulting from entrapment within refrigerators or freezers which havefrequently been reported.

It has been determined (Clinical Research, 18, 2:492 (April 1970) thatthe cause of death among small children entrapped in abandonedrefrigerators is not from lack of oxygen but, rather, is from heat. Inrefrigerators and freezers commonly in use in American households,sufficient oxygen is normally available in such a closed volume tosustain the life of a small child for a substantial period of time. Forexample, clinical tests using dogs showed that average survival time ofsuch dogs to be approximately 4 hours in a closed commercialrefrigerator not connected to a source of electrical power, but thatwhen the refrigerator was on and cold the animals survived for more than24 hours. Maintaining acceptable oxygen levels in the closed inoperablerefrigerator did not significantly extend survival time of the animals;expiration was due to increased temperature within the closed inoperablerefrigerator.

Thus a child entrapped in a closed refrigerator, freezer or the likewould expire because of temperature rise within such an enclosure,generated by the body heat of the entrapped child, the effect of whichis intensified by increased humidity within the enclosure supplied bybody processes of the entrapped child. For example, in an average sizecommercial refrigerator (not operating), the body heat of a child ofabout 30 to about 60 pounds, coupled with the effect of increasedhumidity, would cause a temperature rise of an effective temperature ofabout 1 lF. to about 15F. in about to about 240 minutes followingentrapment; such a child would normally die due to the heat and humidityby the time the enclosure attained a temperature of 96 to 98F. Becauseof oxygen content in the volume of the refrigerator and air leakage atthe door seal, sufficient oxygen should be available to an entrappedchild to sustain him for a considerably longer time except for theeffect of temperature rise within the enclosure as hereinbeforediscussed. Heat transfer calculations show that a gap of about /2 inchat the door is sufficient to maintain the temperature within suchenclosures below acceptable levels, and, also, to provide sufficient aircirculation to prevent suffocation of a child entrapped within suchenclosure.

Various advantages other than prevention of temperature rise andallowance of air circulation are provided by the Refrigerator/FreezerSafety Device herein described: when the device is activated and thedoor of the enclosure is thereby opened, a child therein can readilyhear and be heard, and sufficient light enters the enclosure toilluminate the interior thereof to allow escape of a child therefrom andto reduce the possibility of the child becoming frightened or panicked.

Therefore an urgent need is indicated for a simple, effective, andreliable device for opening and holding open the door of a refrigerator,freezer, icebox or the like, particularly those which have beenabandoned, when the temperature inside such an enclosure exceeds acertain level. Such a device should be compact and easy to install, butmust provide sufficient force when activated to open a magnetically helddoor of a refrigerator, freezer or the like.

The Refrigerator/Freezer Safety Device herein described satisifies theaforementioned need.

SUMMARY OF THE INVENTION This invention comprises a device for openingthe door of an enclosure, particularly a refrigerator, freezer or thelike having a magnetically held door, including a spring-loaded rigidmember which is slideably mounted adjacent an inner surface of the door,a temperature sensing means responsive to the temperature within theenclosure, and a holding means, responsive to the temperature sensingmeans, for holding the rigid member in a retracted position against thetension of the spring, which holding means is released in response tothe temperature sensing means when the temperature within the enclosureexceeds a certain level.

It is therefore an object of this invention to provide a novel safetydevice for refrigerators, freezers and the like.

Another object of this invention is to provide a device for opening amagnetically held door of a refrigerator, freezer or the like to allowsufficient heat dissipation therefrom and air circulation therein toprevent the death of a child which may be trapped therein.

Still another object of this invention is to provide a device to holdopen the door of a refrigerator, freezer or the like to prevent thedeath of a child which may be trapped therein.

It is a further object of this invention to provide a device for openingand holding open a magnetically held door of a refrigerator or freezer,which device is activated by heat.

These and other objects of the invention will become apparent as thedetailed description proceeds.

DESCRIPTION OF THE DRAWINGS The invention will be more clearlyunderstood from the following detailed description of specificembodiments thereof read in conjunction with the accompanying drawingswherein:

FIG. 1 is a cross-sectional view of a preferred embodiment of thepresent invention, illustrating the use of bimetallic disks as atemperature sensing means, and a magnetic solenoid and associated switchand circuitry.

FIG. 2 is a cross-sectional view of another embodiment showing analternative configuration for use of bimetallic disks as a temperaturesensing means and means for releasing the rigid member.

FIG. 3 is a partial view in section of the embodiment of FIG. 2 whichincorporates a volatile liquid as the temperature sensing means andmeans to urge the rigid member against the door of the enclosure.

FIG. 4 is a partial view in section of the embodiment of FIG. 1 whichincorporates a volatile liquid as the temperature sensing means.

DETAILED DESCRIPTION The preferred embodiment of the present inventioncomprises a spring-loaded rigid member which may be held by any suitableholding means in a retracted position against the tension of suchSpring, which holding means is responsive to and released by a suitabletemperature sensing means. Materials of construction and shapes ofelements of the various embodiments of the invention herein describedare not critical so long as the properties of such materials and shapesof such elements permit functioning of the elements of the invention asherein discussed.

As shown in FIG. 1, the rigid member may comprise a shaft 1 which may beslideably mounted within any suitable support or housing 2, whichhousing may be secured by any suitable mounting means (not shown) to thesurface of or within a wall of an enclosure such that the slidingdirection of the shaft 1 is along the axis thereof and substantiallyperpendicular to the plane of door of the enclosure, and on end of shaft1 is immediately adjacent the interior surface of door 10 as shown.Shaft 1 may be held in the retracted position against the tension of asuitable spring 3 by any suitable holding means such as shown in FIG. 1as pin 4 and a slot 5 in shaft 1. A suitable temperature sensing meansmay be located in any convenient position within the enclosure, thepurpose thereof being to sense the temperature within the enclosure andto release the holding means when the temperature within the enclosurereaches a certain level. Any suitable temperature sensing means may beused as are well known in the art, such as curved bimetallic members,fusible links, and thermocouple or thermostat controlled solenoids orswitches, so long as the aforementioned purpose thereof is served. Inthe embodiment shown in FIG. 1,

one or more curved bimetallic disks 6 are mounted axially on pin 4 andprovide both the temperature sensing means and the means for releasingthe holding means, i.e., withdrawing pin 4 from slot 5. In thisembodiment any suitable number of curved bimetallic disks may be useddepending on the amount of travel required to withdraw pin 4 from slot 5upon thermal expansion of the bimetallic disks 6. In operation, shaft 1may be pushed to its retracted position against the tension of spring 3;as the temperature within the enclosure reaches a sufficiently low levelso that the curved bimetallic disks are not fully expanded, pin 4 willseat into slot 5 under the tension of a spring such as leaf spring 7shown in FIG. 1. Whenever the temperature within the enclosure, such asrefrigerator or freezer, exceeds a certain level, bimetallic disks 6will expand suffciently to withdraw pin 4 from slot 5 and therebyrelease shaft 1 to be urged against door 10 of the enclosure by theforce of spring 3. The tension on spring 3 need be only sufficient tobreak the seal on the door 10 of the enclosure. Currently used householdrefrigerators have magnetic seals requiring less than about 15 poundsforce at the handle of the door in order to break the magnetic seal,which would govern the required strength of spring 3 for designpurposes. As hereinbefore discussed, the door of the enclosure need beopened approximately /2 inch to provide suitable heat transfer and aircirculation within the enclosure, which amount of opening governs fordesign purposes the extension which is required of shaft 1 under theinfluence of the force of spring 3.

As also shown in FIG. 1, suitable lockout means may be provided toprevent inadvertant closing of door 10 by external forces which wouldovercome the resistance of spring 3. Such lockout means may berepresented by stop pin 8 slideably mounted within housing 2 which maybe urged under the influence of leaf spring 11 against shaft 1 and intoa slot 9 provided in shaft 1 when shaft 1 is in its extended position.

Also as shown in FIG. 1, certain provisions for automatic retraction ofshaft 1 may be provided. Such automatic retraction may be provided byvarious means, such as a motor drive or a magnetic solenoid. As shown inFIG. 1, a magnetic solenoid may be used, and toward this end, anextension 12 of shaft 1 may be provided as shown and either be anintegral part of shaft 1 or be connected to shaft 1 by any suitableconnecting means such as threaded connection 13. Extension 12 has as amaterial of construction thereof suitable magnetically susceptiblematerial. Magnetic solenoid l4 surrounds a portion of extension 12 ofshaft 1 and is controlled by a suitable switch, such as microswitch 15,which in turn is responsive to movements of the bimetallic disks 6. Itshould be noted that a motor drive (not shown) could be used to retractshaft 1, which motor drive may also be made to be responsive tomicroswitch 15. In the configuration shown, microswitch 15 would be ofthe normally open type. Power to solenoid 14 through microswitch 15 isprovided by the household current (not shown) provided for normaloperation of a refrigerator or freezer. During normal operation of arefrigerator or freezer, power provided to the solenoid by way ofhousehold current results in a retraction of shaft 1 by solenoid 14through the magnetic interaction of the solenoid with extension 12 ofshaft 1. As the temperature within the interior of the refrigerator orfreezer drops, bimetallic disks 6 contract sufficiently to allow pin 4to seat in slot 5 of shaft 1 under the influence of leaf spring 7.Microswitch 15 is controlled by the movement of pin 4 such that when pin4 seats in slot 5, microswitch 15 is opened, thereby cutting off thepower to solenoid 14, resulting in no electric power consumption by thesolenoid during normal (cooled) operation of the refrigerator orfreezer.

An alternative embodiment of the invention may be as shown in FIG. 2wherein the travel imparted to the shaft may be provided directlythrough the thermal expansion of bimetallic disks. But, to avoid therequirement of a sufficient number of bimetallic discs to impart to theshaft the total of approximately inch travel required to adequately openthe door of the enclosure, the shaft may comprise two mating sections 21and 22 slideably mounted within a suitable housing 23. Section 21 has asmall diameter portion on one end thereof, which is received by andslideable within a bore of section 22 as shown. The bore within section22 is sufficiently deep to receive a spring 24. It may be desirable tolimit the extension of section 21 relative to section 22 to avoidinadvertant popping out or locking of section 21 during normal (cooled)operation of the refrigerator or freezer and opening and closing of thedoor thereof. This may be accomplished by providing a hole throughsection 21 along the axis thereof for receiving bolt 33. Section 22 hasa tapped hole at the bottom of the bore therein for receiving thethreaded section of bolt 33 as shown in FIG. 2. Section 21 is free toslide on bolt 33 relative to section 22. Section 21 may have a boretherein to receive the head of bolt 33, the depth of this bore beingsuch that the extension of section 21 relative to section 22 is limitedby the distance between the shoulder of bolt 33 and the bottom of thebore in section 21. I

Bimetallic disks 26 are located within housing 23 in any suitableposition such that thermal expansion of discs 26 provide movement tosection 22 such as by way of a member which may be rigidly connected tosection 22 by any suitable connecting means such as pin 27. A weaktensioning spring 28 may be provided as shown to urge member 25 andsection 22 toward a retracted position against bimetallic disks 26. Astop pin 29 urged by leaf spring 30 against the shaft may be provided tolock the shaft in an extended position under conditions similar to thatdescribed above in association with the embodiment represented inFIG. 1. In operation, when the temperature within the enclosure forwhich the embodiment in FIG. 2 is provided is sufficiently low so thatbimetallic disks 26 are in their contracted condition, tensioning spring28 holds section 22 in a retracted position within housing 23 by urgingagainst member 25. Section 21 is free to reciprocate within section 22under the influence of spring 24 and the opening and closing of the door10. Spring 24 is such that it is of insufficient strength (for example,less than about 7 pounds) to break the magnetic seal such as would beprovided to hold door 30 of the enclosure in a closed position. When thetemperature within the enclosure rises, resulting in expansion of disks26, the force of such expansion urges section 22 toward an extendedposition, and likewise section 21 is urged toward an extended positionby reason of the mating shouldered section 31 of sections 21 and 22.This results in section 21 being urged against the surface of door 10,such force being of sufficient magnitude to break the seal which holdsthe door in a closed position. Spring 24 may be provided of sufiicientstrength to push door 10 open once the magnetic seal is broken by theexpansive force of the bimetallic disks. A stop pin 29 may be slideablymounted within housing 23 in such a position that stop pin 29 will seatinto slot 32 of section 21 when section 21 is in its full extendedposition, i.e., the sum of the extensions provided by spring 24 and theexpansion of bimetallic disks 26.

As shown in FIGS. 3 and 4, still another temperature sensing means maybe incorporated into the embodiments of FIG. 1 and FIG. 2. As shown inFIG. 3, an expandable container 41 may be provided within a suitablehousing or support similar to that for containing the bimetallic disksof the embodiment of FIG. 2. Alternatively, a piston and cylinderarrangement (not shown) could be used. Within expandable container 41 isprovided a suitable liquid 42 whose properties are such that at the lowtemperature of operation of a refrigerator or freezer, the liquid 42does not have signifcant vapor pressure associated therewith, but atroom temperature, about 68F. to about F, the liquid 42 has a vaporpressure significant enough to create pressure within container 41, toexert force on member 25 so as to cause operation of the device in amanner similar to the operation of the embodiment of FIG. 2. Liquidswhich can be used with success include butane; 1,3-butadiene;2,2-dimethyl propane; dichlorodifluoromethane; and 1,2-dichlorol 1 ,2,2-tetrachloroethane. Each of these materials respectively exhibit asignificantly higher vapor pressure at about 80F compared to that whichthey exhibit at about 32F, viz, for butane, about 2.7 atm compared toabout 1.1 atm; for 1,3-butadiene, about 2.9 atm compared to about 1.2atm; for 2,2-dimethyl propane, about 1.8 atm compared to about 0.7 atm;for dichlorodifluoromethane, about 1.9 atm compared to about 0.7 atm;and for l,2-dichloro-l,l ,2,2-tetrachloroethane, about 2.2 atm comparedto about 0.9 atm. It is understood that other materials could be used solong as they exhibited suitable vapor pressure properties.

As shown in FIG. 4, a similar expandable container 43 containing asuitable liquid 42 as hereinbefore described may be used in associationwith the embodiment of FIG. 1 to provide sufficient force to withdrawpin 4 from slot 5 in response to temperature within the enclosure in amanner similar to the operation of disks 6 of the embodiment of FIG. 1.g

It is understood that other configurations as are well known in the artfor containing such liquids may be used to effect operation of theinvention as herein described. For example, a pressure vessel andassociated tubing (not shown) may be used to contain the liquid in anysuitable location withinthe enclosure incorporating this inventionthrough which vapor pressure may be transmitted to provide forcesnecessary to effect operation of the embodiments of FIGS. 3 and 4.

Other details of construction of the invention herein described may beapplied as might occur to one skilled in the art, and have therefore notbeen shown in complete detail. Other embodiments may be developedwithout departing from the spirit and scope of this invention.

We claim:

1. A device for opening the door of an enclosure, particularly arefrigerator or freezer having a magnetically held hinged door, whichcomprises: a rigid member slideably mounted to a wall structure adjacentthe door of the enclosure, the sliding direction thereof beingsubstantially perpendicular to the plane of the door of the enclosure; aspring biasing said rigid member along the sliding direction thereofagainst the force holding closed the door of the enclosure; means forholding said rigid member in a retracted position against the bias ofsaid spring; and temperature sensing means comprising a curvedbimetallic member, said curved bimetallic member engaging said holdingmeans, said holding means being responsive to said temperature sensingmeans and releaseable in response to said temperature sensing means whenthe temperature within the enclosure exceeds a certain level.

2. A device as recited in claim 1 further comprising: an extension ofsaid rigid member, said extension composed of magnetically susceptiblematerial; an electrically powered solenoid surrounding said extensionfor magnetically attracting said extension when electric power isapplied to said solenoid, thereby retracting said rigid member againstthe biasing force of said spring; and a switch, responsive to saidtemperature sensing means, for regulating electric power to saidsolenoid.

3. A device for opening the door of an enclosure, particularly arefrigerator or freezer having a magnetically held hinged door, whichcomprises a rigid member slideably mounted to a wall structure adjacentthe door of the enclosure, the sliding direction thereof beingsubstantially perpendicular to the plane of the door of the enclosure; acurved bimetallic member engaging said rigid member, for urging saidrigid member along the sliding direction thereof against the forceholding closed the door of the enclosure, to open the door when thetemperature within the enclosure exceeds a certain level.

4. A device for opening the door of an enclosure, particularly arefrigerator or freezer having a magnetically held hinged door, whichcomprises: a rigid member slideably mounted to a wall structure adjacentthe door of the enclosure, the sliding direction thereof beingsubstantially perpendicular to the plane of the door of the enclosure; aspring biasing said rigid member along the sliding direction thereofagainst the force holding closed the door of the enclosure; means forholding said rigid member in a retracted position against the bias ofsaid spring; and an expandable container and a volatile liquid containedwithin said expandable container, said expandable container engagingsaid holding means, said holding means being responsive to expansion ofsaid expandable container and releaseable in response to said expansionwhen the temperature within the enclosure exceeds a certain level.

5. In a refrigeration unit comprising an enclosure having a magneticallyheld hinged door and a device for opening the door, the improvementcomprising, a rigid member slideably mounted to a wall structureadjacent the door of the enclosure, the sliding direction thereof beingsubstantially perpendicular to the plane of the door of the enclosure; aspring biasing said rigid member along the sliding direction thereofagainst the force holding closed the door of the enclosure; means forholding said rigid member in a retracted position against the bias ofsaid spring; temperature sensing means comprising a curved bimetallicmember, said curved bimetallic member engaging said holding means, saidholding means being responsive to said temperature sensing means andreleaseable in response to said temperature sensing means when thetemperature within the enclosure exceeds a certain level; an extensionof said rigid member, said extension composed of magneticallysusceptible material; an electrically powered solenoid surrounding saidextension for magnetically attracting said extension when electric poweris applied to said solenoid, thereby retracting said rigid memberagainst the biasing force of said spring; and a switch, responsive tosaid temperature sensing means,

for regulating electric power to said solenoid.

1. A device for opening the door of an enclosure, particularly a refrigerator or freezer having a magnetically held hinged door, which comprises: a rigid member slideably mounted to a wall structure adjacent the door of the enclosure, the sliding direction thereof being substantially perpendicular to the plane of the door of the enclosure; a spring biasing said rigid member along the sliding direction thereof against the force holding closed the door of the enclosure; means for holding said rigid member in a retracted position against the bias of said spring; and temperature sensing means comprising a curved bimetallic member, said curved bimetallic member engaging said holding means, said holding means being responsive to said temperature sensing means and releaseable in response to said temperature sensing means when the temperature within the enclosure exceeds a certain level.
 2. A device as recited in claim 1 further comprising: an extension of said rigid member, said extension composed of magnetically susceptible material; an electrically powered solenoid surrounding said extension for magnetically attracting said extension when electric power is applied to said solenoid, thereby retracting said rigid member against the biasing force of said spring; and a switch, responsive to said temperature sensing means, for regulating electric power to said solenoid.
 3. A device for opening the door of an enclosure, particularly a refrigerator or freezer having a magnetically held hinged door, which comprises a rigid member slideably mounted to a wall structure adjacent the door of the enclosure, the sliding direction thereof being substantially perpendicular to the plane of the door of the enclosure; a curved bimetallic member engaging said rigid member, for urging said rigid member along the sliding direction thereof against the force holding closed the door of the enclosure, to open the door when the temperature within the enclosure exceeds a certain level.
 4. A device for opening the door of an enclosure, particularly a refrigerator or freezer having a magnetically held hinged door, which comprises: a rigid member slideably mounted to a wall structure adjacent the door of the enclosure, the sliding direction thereof being substantially perpendicular to the plane of the door of the enclosure; a spring biasing said rigid member along the sliding direction thereof against the force holding closed the door of the enclosure; means for holding said rigid member in a retracted position against the bias of said spring; and an expandable container anD a volatile liquid contained within said expandable container, said expandable container engaging said holding means, said holding means being responsive to expansion of said expandable container and releaseable in response to said expansion when the temperature within the enclosure exceeds a certain level.
 5. In a refrigeration unit comprising an enclosure having a magnetically held hinged door and a device for opening the door, the improvement comprising, a rigid member slideably mounted to a wall structure adjacent the door of the enclosure, the sliding direction thereof being substantially perpendicular to the plane of the door of the enclosure; a spring biasing said rigid member along the sliding direction thereof against the force holding closed the door of the enclosure; means for holding said rigid member in a retracted position against the bias of said spring; temperature sensing means comprising a curved bimetallic member, said curved bimetallic member engaging said holding means, said holding means being responsive to said temperature sensing means and releaseable in response to said temperature sensing means when the temperature within the enclosure exceeds a certain level; an extension of said rigid member, said extension composed of magnetically susceptible material; an electrically powered solenoid surrounding said extension for magnetically attracting said extension when electric power is applied to said solenoid, thereby retracting said rigid member against the biasing force of said spring; and a switch, responsive to said temperature sensing means, for regulating electric power to said solenoid. 